Circuit disconnect assembly

ABSTRACT

A circuit disconnect assembly for a high-voltage electrical storage device in a vehicle integrates a grip portion and a fuse holder portion into one unit. The handle is easily manipulated manually within a housing of the storage device to open a high-voltage circuit and allow quick replacement of the fuse. The handle is manually shiftable between a locked state and an unlocked state to connect and disconnect the fuse from the circuit.

TECHNICAL FIELD OF INVENTION

The present invention relates generally to electrical storage devicesfor vehicles, and more particularly to a service disconnect for avehicle traction battery system.

BACKGROUND OF THE INVENTION

High-voltage electrical storage devices, such as high-voltage tractionbatteries, are used in electric, hybrid electric, and fuel cellvehicles. A high-voltage electrical circuit formed by the electricalstorage device and a powertrain system connected to the storage deviceshould be electrically isolated from the vehicle and the vehicleoccupants at all times.

Traction batteries in today's electric and hybrid electric vehiclestypically operate at voltages in excess of conventional accessorybatteries. As such, service personnel require convenient and reliabletechniques for opening the traction battery circuit and/or replacingfuses and other system components.

Currently known methods for opening a high-voltage electrical storagedevice and accessing the fuse tend to be cumbersome because they requiremultiple steps and components to remove the fuse. Therefore, there is adesire for a device that can reliably and expediently open thehigh-voltage circuit and allow replacement of a spent fuse in the highvoltage circuit.

SUMMARY OF THE INVENTION

The invention is directed to a disconnect assembly that electricallyisolates a high-voltage bus of an electrically-powered vehicle. Thedisconnect assembly is designed to hold a fuse in a high-voltageelectrical storage device within an electrically isolated electricalcircuit and to be easily manipulated to open the high-voltage circuit.At least one portion of the disconnect assembly is removable to allowquick replacement of the fuse. The disconnect assembly may be designedso that it must be removed before any other components in thehigh-voltage electrical storage device can be accessed.

In one embodiment, the disconnect assembly includes a handle designed toretain the fuse in the high-voltage circuit. The handle is manuallyshiftable within a housing in the electrical storage device between alocked position and a unlocked position to lock and unlock the fuse,thereby closing and opening the circuit. A handle body prevents any partof the assembly from being removed unless the handle is shifted to theunlocked position.

These and other features of the present invention can be best understoodfrom the following specification and drawings, the following of which isa brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an assembly according to oneembodiment of the invention;

FIG. 2 illustrates one example of a top view of the assembly of FIG. 1;

FIGS. 3A and 3B are a perspective view and a bottom plan view,respectively, of the assembly according to another embodiment of theinvention;

FIGS. 4A and 4B are schematic section views of a relationship between afuse and mating terminals; and

FIGS. 5A and 5B are schematic section views of another relationshipbetween the fuse and mating terminals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is an exploded perspective view of a disconnect assembly 100according to one embodiment of the invention. Generally, the disconnectassembly 100 is incorporated in a high-voltage electrical storage device102 to quickly and reliably isolate high-voltage terminals in the device102 from the rest of an electrical system, such as a high-voltagepowertrain system (not shown) without removing a fuse from the devicealtogether in doing so. The disconnect assembly 100 also provides aconvenient way to remove and service a spent fuse.

As shown in FIG. 1, the disconnect assembly 100 includes a handle thatintegrates an upper grip portion 104 a and a lower fuse holder portion104 b together into a single unit. The handle 310 is designed to engagewith a housing 106 disposed on the electrical storage device. Thehousing 106 is fixed to or integral with the electrical storage device102 and does not move relative to the electrical storage device 102, norcan it be removed when the handle is removed. Mating terminals 108(e.g., FIGS. 4A and 4B) separate a series connections of circuitsegments, such as electrochemical cells or batteries 400, 404 (shownschematically), inside the electrical storage device 102. The matingterminals 108 include one positive terminal and one negative terminalthat can be connected together by a fuse 110. In one embodiment, themating terminals 108 divide the series connections into two halves,thereby cutting the voltage across the mating terminals 108 by half.This is preferable because it reduces the voltage to its lowest possiblelevel when opening the circuit formed by the segments in only onelocation. The mating terminals 108 may be disposed in the housing 106 orin another structure in the electrical storage device 102.

The handle is designed to be retained securely in the housing 106 andhold a fuse 110 or other circuit connector in the fuse holder portion104 b. When the fuse 110 is connected to the mating terminals 108,current flows through the fuse 110 from the positive mating terminal tothe negative mating terminal. If the current flowing through the fuse110 reaches an excessively high level and/or flows for an excessiveduration, the fuse 110 will burn open, opening the circuit andpreventing further current flow between the mating terminals 108. Boththe handle and the fuse 110 are serviceable items in the electricalstorage device 102.

The grip portion 104 a of the handle acts as a user interface to allow aworker to easily connect and disconnect the fuse 110 from the matingterminals 108. In one embodiment, the grip portion 104 a and the fuseholder portion 104 b can be shifted together via rotation or othermovement into either a locked position, where the fuse 110 is connectedto the mating terminals 108 so that the electrical storage device 102 isready to operate, or a unlocked position, where the mating terminals 108are open to prevent current flow and allow the high voltage powertrainand external portions of the electrical storage device 102 to beaccessed. The grip portion 104 a can be manually moved to and fromeither position without actually removing the handle or the fuse 110from the housing 106. The examples described below illustrate variouspossible structures that allow engagement and removal of the handle,which includes both the grip portion 104 a and the fuse holder portion104 b. Regardless of the specific structure, however, the handle shouldbe designed to require application of moderate force (e.g., squeezingand/or pressing force) to disengage any detent in the handle and/or thehousing 106 before it can be shifted free of the mating terminals 108and, if needed, lifted out of the housing 106.

In the embodiment shown in FIG. 1, the grip portion 104 a of the handleincludes a handle body 112 and a retention feature 114. A fuse connector116 couples the fuse 110 to the handle body 112 so that manual shiftingof the handle body 112 will shift the fuse 110 as well. The fuse holderportion 104 b of the handle includes a fuse retainer 118 that holds thefuse 110. As shown in FIG. 1, a body portion 120 of the fuse 110 is atleast partially enclosed between the fuse connector 116 and the fuseretainer 118. Terminals 121, such as first fuse terminal 330 and secondfuse terminal 340, in the fuse 110 remain exposed outside the fuseconnector 116 and the fuse retainer 115 in the handle so that they canconnect to the mating terminals 108. Fasteners 122, such as throughbolts, extend through the fuse retainer 118, the fuse connector 116, andthe handle body 112 to connect them together so that they move as oneunit. Each of these handle components will be described in greaterdetail below.

Both the grip portion 104 a and the fuse holder portion 104 b of thehandle may be made of any suitable electrically-insulating material,such as plastic. To prevent the grip portion 104 a from shifting toofreely in the housing 106 or otherwise disengaging from the housing 106,the retention feature 114 has a detent 300, such as tab 124, to hold thegrip portion 104 a and/or the fuse holder portion 104 b in the housing106. In the embodiment shown in FIG. 1, the retention feature 114includes at least one tab 124 designed to engage with at least onecorresponding recess 126 in the housing 106. The retention feature 114in this case is made of a resilient material and has a V-shaped groove128 that accommodates a substantially planar projection 130 on thehandle body 112.

When a worker applies a squeezing or pinching force on opposingdepressions 132 in the direction of arrow B and the direction of arrow Cof the retention feature 114, side walls 134 of the retention feature114 move inward toward each other. The inward movement of the side walls134 disengages the tab 124 on the retention feature 114 from the recess126 in the housing 106, freeing the retention feature 114 to shift inthe direction of arrow D within the housing 106. The resiliency of theretention feature 114 causes the side walls 134 to move back outwardwhen the tab 124 aligns with the recess 126 so that the tab 124 engageswith the recess 126. Also, pulling upward on the handle body 112 whenthe tab 124 is not engaged with the recess 126 and when the fuse blades121 are aligned with openings, such as a first set of ruse channels 210,in the housing 106 allows the grip portion 104 a and the fuse holderportion 104 b, therefore the fine 110 encased therein, to be lifted outof the electrical storage device 102 for service.

As shown in FIG. 2, the retention feature 114 may have several tabs 124opposite each other, and the housing 106 may have several pairs ofcorresponding recesses 126 a, 126 b. The tabs 124 engage a first set ofrecesses 126 a when the handle (i.e., the grip portion 104 a and thefuse holder portion 104 b) and the fuse 110 are in the locked positionand engage a second set of recesses 126 b when the handle and the fuse110 are in the unlocked position. The engagement between the tabs 124and the recesses 126 a, 126 b prevent the grip portion 104 a of thehandle from shifting once it is placed in a designed position. Ofcourse, it is possible to place the tabs on the housing and the recesseson the retention feature without departing from the scope of theinvention.

A limit switch 129 may also be incorporated in the housing 106 near therecesses 126 a, 126 b and in communication with a processor (not shown).The tab 124 is configured so that it closes the limit switch 129 when itengages with one of the recesses 126 a, 126 b, allowing vehicleelectronics to detect the position of the handle and the fuse 110 andconfirm that it is inserted correctly in a selected position. The limitswitch 129 may also act as a positive override of any system failure(e.g., failed software, electrical and/or mechanical systems) duringstorage and shipment of a damaged electrical storage device.

The engagement between the grip portion 104 a of the handle and thehousing 106 of the electrical storage device 102 can prevent an accesscover 138 of the electrical storage device 102 from being removed unlessthe handle is removed first. In one embodiment, the retention feature114 is held between a flange 140 on the handle and a flat portion 142 ofthe housing 106 when the handle is in the unlocked position and thelocked position. Also, the fuse blades 121 are held securely between themating terminals 108 to prevent the fuse 110 from being lifted out ofthe housing 106 from the locked position. As a result, the access cover138 cannot be removed while the handle is connected to the housing 106.

The disconnect assembly 100 may be designed with a stowage feature sothat the handle can be easily stowed in the service position to preventit from becoming damaged or lost during service. For example, a tether144 may be attached to the grip portion 104 a and the housing 106.Alternatively, a second set of fuse channels 212 in the housing 106 maybe included to allow the grip portion 104 a and the fuse holder portion104 b of the handle to be inserted in a service position. The shape ofthe handle acts as the stowage feature in this case. In the serviceposition, the fuse 110 is completely isolated from the mating terminals108 and the grip portion 104 a (and therefore the fuse 110) is notdirectly shiftable to either the unlocked or locked position. To movethe handle back to the unlocked position so that is shiftable to thelocked position, the fuse blades 121 are aligned with the second set offuse channels 212 so that the handle can be completely removed from thehousing 106 out of the service position. The fuse blades 121 are thenaligned with the first set of fuse channels 210 and the handle isreinserted into the housing 106 in the unlocked position.

FIGS. 3A and 3B illustrate the disconnect assembly 100 according toanother embodiment of the invention. FIG. 3A is a perspective view of analternative handle 104 c that is separated from an alternative housing106 c. For simplicity, the handle 104 c in this embodiment collectivelyrefers to the combined unit having the grip portion and the fuse holder.FIG. 3B is a bottom plan view (i.e., a view taken from inside theelectrical storage device 102 looking upward into the housing 106 c)when the handle 104 c is placed inside the housing 106 c and left intothe unlocked position. In this embodiment, two high voltage pins 250 areconnected to the fuse blades 121. When the handle 104 c is inserted intothe housing 106 c in the unlocked position, the pins 250 engage withcorresponding holes 252 in the housing 106 c to form the high voltageconnection. The high voltage connection itself can be, for example, aresilient connection structure made by Anphenol(R).

The handle 104 c in this embodiment also includes a pair of retainers254, such as T-shaped retainers, designed to engage with correspondingfirst openings 256 and second openings 258 in the housing. Like theprevious embodiment, the handle body 112 of the handle 104 c can bemanually shifted. The retainers 254 act as the retention feature andeach have a neck (not shown) so that the retainers 254 can be heldsecurely in at least one of the openings 256, 258.

In the illustrated embodiment, each of the first openings 256 has anelongated shape so that the retainers 254 can be shifted via rotationbetween a first portion corresponding to the unlocked position 256 a anda second portion corresponding to the locked position 256 b. The secondportion 256 b may be smaller than the rest of the first opening 256 sothat the first opening 256 securely holds the neck of each retainer 254while the handle 104 c is shifted, preventing the handle 104 c frombeing lifted out of the housing 106 c from any position other than theunlocked position during shifting. The retainers 254 may also beresiliently biased so that shifting can occur only after enough forcehas been applied to overcome the biasing force before the handle 104 cshifts; thus, the retainers 254 in this case also act as the detent.

The second openings 258 correspond to the service position. As shown inFIGS. 3A and 3B, the second openings 258 are completely separate fromthe first openings 256, making it impossible for the handle 104 c to beshifted from the second openings 258 to the first openings 256 withoutfirst removing the handle 104 c from the housing 106 c. Also, the pins250 are disengaged from the holes 252 when the handle 104 c is in theservice position and are simply suspended freely from the fuse blades121. Thus, the handle 104 c must be lifted out of the housing 106 cbefore the handle 104 c can be placed into or out of the serviceposition. As a result, when the electrical storage device 102 is shippedor serviced, the retainers 254 engage with the second openings 258without any danger of inadvertently slipping into the first openings256.

FIGS. 4A and 4B illustrate one possible relationship between the matingterminals 108 and the fuse terminals 121. FIG. 4A shows the fuse 110 inthe unlocked position and FIG. 4B shows the fuse 110 in the lockedposition. As noted above, the mating terminals 108 include a positiveterminal and a negative terminal and separate the series connections ofelectrochemical cells in the electrical storage device 102 into twohalves that can be connected only by inserting the fuse 110 in thelocked position. Dividing the series connection in half reduces theelectrical potential inside the electrical storage device 102 by halfwhen the fuse 110 is unlocked for service.

The mating terminals 108 are generally planar and arranged in a spacedrelationship to form an open circuit. The mating terminals 108 may eachhave a bent portion 200 at one end to guide the fuse terminals 121 intoa locked position. As shown in FIG. 4A, shifting the handle shifts thefuse terminals 121 toward the mating terminals 108. Once the handle andthe fuse 110 are in the locked position (FIG. 4B), the mating terminals108 are linked by the fuse terminal 121, allowing current to pass fromthe positive mating terminal to the negative mating terminal.

In one embodiment, the fuse terminals 121 reach the locked position onlyafter they are positioned securely between the mating terminals 108; inother words, the locked position require more than just mere contactbetween the mating terminals 108 and the fuse terminals 121. Thisensures that vibrations or other typical vehicle forces do notdisconnect the fuse 110 unexpectedly. Moreover, it is impossible toremove the fuse 110 from the housing 106 while it is in the lockedposition because the fuse terminals 121 are sandwiched between theplanar mating terminals 108, which prevent vertical displacement of thefuse 110. Thus, the fuse 110 can be easily removed and serviced whilekeeping the rest of the electrical storage device 102 intact.

FIGS. 5A and 5B illustrate a variation of the structure shown in FIGS.4A and 4B. In this example, the fuse terminals 121 have a notch 202 thatengages with an bump 204 formed in at least one of the mating terminals108. The relative dimensions between the bump 204 and the fuse terminals121 are selected so that the notch 202 engages with the bump 204 withoutrequiring excessive force. The engagement between the bump 204 and thenotch 202 provides an added measure of security in the connectionbetween the mating terminals 108 and the fuse terminals 121.

It should be understood that various alternatives to the embodiments ofthe invention described herein may be employed in practicing theinvention. It is intended that the following claims define the scope ofthe invention and that the method and apparatus within the scope ofthese claims and their equivalents be covered thereby.

1. An electrical storage device assembly for a vehicle, comprising: ahousing disposed on a vehicular electrical storage device; a gripportion that is manually shiftable within the housing between a lockedposition and an unlocked position; and a fuse holder portion integratedwith the grip portion, wherein the fuse holder portion is adapted tooperably connect a fuse to the grip portion such that shifting of thegrip portion shifts the fuse between the locked position and theunlocked position, the fuse in communication with the vehicularelectrical storage device in the locked position.
 2. The assembly ofclaim 1, wherein the grip portion and the fuse holder portion areshiftable via rotation.
 3. The assembly of claim 1, wherein the fuseholder portion includes a fuse retainer that at least partially enclosesthe fuse.
 4. The assembly of claim 1, wherein the grip portion includesa retention feature, the retention feature preventing shifting of thefuse portion to at least one of the locked position and the unlockedposition until a predetermined force is applied to the retention featurein a direction different from a direction of shifting.
 5. The assemblyof claim 4, wherein the retention feature prevents shifting from boththe locked position and the unlocked position until the predeterminedforce is applied to the retention feature.
 6. The assembly of claim 4,wherein the retention feature has one of a protrusion and a hole toreceive the protrusion and the housing has the other of the protrusionand the hole, the protrusion preventing shifting of the fuse portion inthe housing when in the hole.
 7. The assembly of claim 1, wherein thegrip portion and the fuse holder portion are removable from the housing.8. The assembly of claim 7, further comprising a stowage featureengaging the grip portion to the housing when the fuse portion is nolonger in communication with the vehicle electrical storage device, thestowage feature precluding shifting of the fuse portion into at leastone of the locked position and the unlocked position when the gripportion is at least partially disposed in the housing.
 9. The assemblyof claim 7, wherein the housing has a profile to accommodate the gripportion in the housing in a service position that blocks the gripportion from shifting within the housing from the service position tothe unlocked position and the locked position.
 10. An electrical storagedevice assembly for a vehicle, comprising: an electrical storage devicehousing; a positive mating terminal spaced from a negative matingterminal, the positive mating terminal and the negative mating terminalin communication with the electrical storage device; and a handle havinga grip portion and a fuse holder portion, the grip portion manuallyshiftable within the electrical storage device housing between a lockedposition and an unlocked position, the fuse holder portion integratedwith the grip portion, wherein the fuse holder portion is adapted tooperably connect a fuse to the grip portion such that shifting of thegrip portion shifts the fuse between the locked position, in which thefuse connects the positive mating terminal and the negative matingterminal to form a closed circuit with the electrical storage device andthe unlocked position, in which the fuse disconnects the positive matingterminal from the negative mating terminal to form an open circuit withthe electrical storage device.
 11. The device of claim 10, wherein theelectrical storage device comprises a plurality of batteries, whereinthe plurality of batteries are divided between the positive matingterminal and the negative mating terminal into two portions, and whereinthe handle connects and disconnects the two portions.
 12. The device ofclaim 10, wherein the fuse has a first fuse terminal and a second fuseterminal, the positive mating terminal and the negative mating terminalboth contacting the first fuse terminal when the fuse is in the lockedposition.
 13. The device of claim 10, wherein the grip portion has oneof a protrusion and a hole to receive the protrusion and the electricalstorage device housing has the other of the protrusion and the hole, thehole and protrusion preventing shifting from at least one of the lockedposition and the unlocked position.
 14. The device of claim 10, furthercomprising a detent in at least one of the electrical storage devicehousing and the handle to engage the handle with the electrical storagedevice housing in at least one of the unlocked position and the lockedposition, wherein the detent disengages when a force is applied to thehandle in a direction different from a direction of shifting of thehandle.
 15. The device of claim 10, including a limit switch to detectwhen the handle is engaged in the electrical storage device housing. 16.The device of claim 10, wherein the handle is removable from thehousing.
 17. The device of claim 10, further comprising a stowagefeature for storing the handle, the stowage feature preventing shiftingof the handle into at least one of the unlocked position and the lockedposition.
 18. The assembly of claim 1, wherein the housing is disposedon an access cover of the vehicular electrical storage device, the gripportion at least partially securing the access cover to the vehicularelectrical storage device.
 19. The assembly of claim 10, wherein theelectrical storage device housing includes an access cover, the handleat least partially securing the access cover to the electrical storagedevice.